Traceable Solid Core Projectile

ABSTRACT

A solid projectile useful in a round of gun ammunition wherein, upon striking a target, the projectile selectively disintegrates, leaving intact at least one portion or appurtenance of the projectile which is recoverable for purpose of identification of rifling markings thereon and/or other analysis.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation-In-Part Application of U.S. patentapplication Ser. No. 12/029,136, filed Feb. 11, 2008, entitled:Traceable Frangible Projectile, which application is a non-provisionalapplication based upon and claiming priority upon ProvisionalApplication Ser. No. 60/949,101, filed Jul. 11, 2007, entitled:Traceable Frangible Projectile, both of which are incorporated herein intheir entirety and upon which priority is claimed.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

FIELD OF INVENTION

This invention relates to the tracing of a spent bullet (projectile) tothe gun from which the projectile was fired. More particularly, thisinvention relates to the traceability of a solid core projectile to thegun from which such solid core projectile was fired.

BACKGROUND OF THE INVENTION

Traceability of a spent projectile to the gun from which it was fired isa major factor in criminology. Commonly a projectile designed to befired from a gun comprises a soft metal jacket housing a solid corewhich disintegrates into individual particulates upon striking a target.When such projectile is fired from a gun having a rifled barrel, therifling internal of the barrel imparts a “signature” to the outersurface of the jacket (or the outer surface of a solid core) as theprojectile moves through and out of the barrel. Commonly, no one of suchparticulates is of a size and/or nature such that forensic examinationof the particulates will provide credible evidence as to the markings onthe projectile which may be useful in tracing the markings back to thegun from which the projectile was fired. In many commonly knownprojectiles which comprise a metallic jacket housing a solid metal core,both the jacket and the core fully disintegrate upon striking a target.Thus, no part of the such projectiles is recoverable and useful asenables a criminologist to identify any markings on the jacket whichmight be valuable in identifying the gun from which the projectile wasfired.

Referring to FIG. 1, there is depicted one embodiment of a prior artprojectile comprising an outer metallic jacket and an internallycaptured solid metallic core. This depicted embodiment comprises acup-shaped metal jacket 12 having a closed trailing end 14 and an openleading end 16. This jacket houses therein a core 18 and commonly formedfrom a malleable metal, combination of metals, metal alloys, orpolymeric materials in combination with one or more metallic materials.In one embodiment, the core of this projectile is formed under pressurein a die. One such core may be disposed within the jacket and theleading end of the jacket closed, at least to the extent required toretain the core within the jacket prior to any firing of the projectilefrom a gun. Commonly, the closing of the jacket and core includesformation of an ogive 22 on the leading end of the projectile.

Upon a projectile as described above and depicted in FIG. 1, striking asolid, semi-solid or hydraulic target, both the jacket and the coredisintegrate into individual particulates which are substantiallyuseless for purposes of attempting to trace the bullet back to the gunwhich fired the projectile. this disintegration feature of theprojectile is useful and desirable for establishing limited penetrationof the projectile into a target, enhanced destructive capability, and/orprevention of undesirable ricochet of the projectile and accompanyingunacceptable collateral damage, particularly injury or death of anunintended target, such as innocent bystanders.

BRIEF SUMMARY OF THE INVENTION

According to one aspect of the present invention, the present inventorprovides a projectile useful in a round of gun ammunition wherein, uponstriking a target, the projectile selectively disintegrates, leavingintact at least one portion or appurtenance of the projectile which isrecoverable for purposes if identification of rifling markings thereonand/or other analysis thereof.

In one aspect of the present invention, the inventor provides forstructuring the projectile to include a disintegration-limiter factorwhich establishes selective disintegration of the projectile when thefired projectile strikes a target, while also providing for a selectedportion of the projectile bearing rifling marking to remain intact uponstriking the target. This structuring of the projectile may take theform of structural design of the jacket in the region thereof mostadjacent the trailing end thereof or, in another embodiment, it may takethe form of incorporation into the projectile of an appurtenance whichtakes on indentifying rifling marking as the projectile passes throughthe rifled barrel of a gun and which survives intact upon disintegrationof the core upon the projectile striking a target.

The disintegration-limiting factor may take on several forms, but ineach form, the projectile is designed to disintegrate upon striking atarget, such disintegration commencing at the leading end of theprojectile and promulgating toward the trailing end of the projectile.Such limiter factor may be formed integrally of the jacket and/or may bein the form of an appurtenance supplied to the frangible core of theprojectile. such limiter factor may be formed integrally of the jacketand/or may be in the form of an appurtenance supplied to the frangiblecore of the projectile. Such limiter factor effectively either retardsor halts the promulgation of disintegration of the core and resultantintact survival of at least an appurtenance or a portion of theprojectile disposed proximate the trailing end of the projectile,resulting in preservation of an intact recoverable portion of theprojectile having rifling markings thereon.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic sectional representation of a projectile of theprior art;

FIG. 2 is a schematic sectional representation of one embodiment of aprojectile embodying various features of the present invention;

FIG. 3 is a schematic sectional representation of a further embodimentof a projectile embodying various features of the present invention;

FIG. 4 is a schematic sectional presentation of one embodiment of adual-core projectile embodying various features of the presentinvention;

FIG. 5 is a schematic sectional representation of a still furthersingle-core embodiment of a projectile embodying various features of thepresent invention;

FIG. 6 is a schematic sectional representation of a further embodimentof a dual-core projectile embodying various features of the presentinvention;

FIG. 7 is a schematic sectional representation of a still furtherembodiment of a dual-core projectile embodying various features of thepresent invention;

FIG. 8 is a schematic sectional representation of an embodiment of amulti-core projectile as depicted in FIG. 7 which employs strips of softmetal affixed to the outer surface of the cores, and a trailing end cap;

FIG. 9 is a side elevational representation of a round of ammunitionincluding one embodiment of a projectile of the present invention;

FIG. 10 is a schematic representation of an enlarged portion of aprojectile of the present invention as recovered intact from a targetand depicting rifling marking thereon;

FIG. 11 is a representation of a typical gel block into which afrangible projectile of the present invention has been fired anddepicting a typical dispersion of the disintegrated particulates of theprojectile when it strikes the gel block; and,

FIG. 12 is a schematic sectional representation of a single-coreembodiment of a projectile as depicted in FIG. 5 but including a discembedded within the core and embodying various features of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with one aspect of the present invention there is provideda round of ammunition 11 (FIG. 9) comprising a projectile 10 (seeFIG. 1) embodying various of the features of the present invention. Tothis end, the projectile as depicted in FIG. 1 includes a cup-shapedjacket 12 is formed from a relatively soft metal, such as brass orcopper. Internally of this jacket there is disposed a solid core 18formed of at least one, or a mixture of metallic materials 20. Suitablemetals are known in the art, and include heavy metals such as tungsten,uranium, tantalum and like metals, and lighter metals such as tin,copper, zinc and like metals. Other metals, metal alloys or combinationof metals such as ferrotungsten metal carbides or the like, may beemployed. In certain applications, the material from which the core isformed may be a non-metal such as polymeric material. Most commonly, thecore is formed into a self0supporting compact, preferably at about roomtemperature and forming pressures, e.g. between a few hundred psi andmultiple thousands psi, depending in part upon the intended product andthe core material employed.

Variations of the present projectile are depicted in FIGS. 2-8. In eachdepicted variant, the core 18 of the projectile 10 will at leastsubstantially disintegrate to the extent that when the projectilestrikes a solid, semi-solid, or hydraulic target, such disintegrationinto individual particulates (both core particulates and jacketparticulates) commences proximate the leading end 16 of the projectileand promulgates along the length of the projectile in a direction towardthe trailing end 14 of the projectile.

At the outset and by way of example, it will be recognized thatprojectile fired from 10-06 caliber rifle having a 1 in 10 twist willexit the rifle muzzle at about 2900 ft/sec and will rotate about itslongitudinal centerline at about 208,000 rpm over a distance of at least200 yards, for example. At this velocity and rate of rotation,disintegration of the projectile upon striking a target will occur overa period of time measured in nanoseconds. Accordingly, it is further tobe recognized that the total disintegration discussed herein takes placeover a time period of a few nanoseconds. Irrespective of this timefactor, the present inventor has found that the alteration of thedisintegration of the projectile along its length as provided by thepresent invention can be varied over a wide range of values by a widerange of techniques employing a disintegration limiter factor, toproduce dramatic terminal ballistics upon the projectile striking atarget, such as a standard gel block commonly employed in the industryfor visually demonstrating the terminal ballistics of a projectile firedfrom a gun.

A typical projectile of the prior art is depicted in FIG. 1 and includesa cup-shaped jacket, commonly formed of a soft metal and having a closedtrailing end 14 and an open leading end 16. Housed within the jacket isa core 18. Commonly, the open leading end of the jacket is at leastpartially closed about the leading end of the core. As described thisclosure may include defining an ogive 22 on the leading end of theprojectile. Also commonly, the leading end of the projectile may includea meplat cavity 26.

With reference to FIGS. 2-5, one embodiment of a projectile 10 embodyingvarious aspects of the present invention, comprises a cup-shaped jacket12, which is closed at its trailing end 14 and open at its leading end16. In FIGS. 2-7, the projectile is depicted in an incomplete form atits leading end in particular inasmuch as the Figures are intended todepict those features which are paramount to the present invention. Ineach of FIGS. 2-5, the jacket includes a solid core 18 as describedhereinabove.

With further reference to FIG. 2 it will be noted that the thickness ofthe jacket wall 28 proximate the trailing end 14 of the jacket ismaterially thicker than the wall thickness of the jacket proximate theleading end of the jacket. In this embodiment, when the projectile isfired from a gun having a rifled barrel, the outer surface 30 of thejacket is marked with the pattern of the rifling. When the projectilestrikes a solid, semi-solid or a hydraulic target, such as the body ofan animal, disintegration of the core and the jacket commences at theleading end of the projectile and propagates toward and through thetrailing end of the projectile. The commencement of the thickening ofthe wall of the jacket at a location 24 approximately midway between theleading and trailing ends of the jacket, initiates the limiter factor ofthis embodiment. By reason of the greater (increasing) wall thickness ofthe jacket proximate the trailing end of the jacket, deterrence of thedisintegration of the projectile begins upon the propagation of thedisintegration reaching this limiter factor. Deterrence of thedisintegration progress along the length of the projectile continues toincrease with the increase in wall thickness of the jacket. Accordingly,when the disintegration of the projectile has progressed to the thickestwall section of the jacket proximate the trailing end of the projectile,such disintegration fails to disintegrate at least a portion 32 of thejacket proximate the trailing end of the jacket, leaving intact suchportion 32 of the jacket, thereby preserving the rifling markings on theouter surface 34 of this intact portion of the trailing end of theprojectile. Notably, in this embodiment of the present invention, thedisintegration of the projectile is not abruptly halted. Rather, theprogression and intensity of disintegration of the projectile decreasesas a function of the increasing wall thickness of the jacket resultingin a portion of the jacket proximate the trailing end of the projectileremaining intact and therefore recoverable for examination of therifling markings on the outer surface thereof.

In this embodiment, the increase in the wall thickness of the jacket maycommence at a location 24 about midway between the leading and trailingends of the jacket, and preferably at a location between the trailingend of the jacket and the midway location 24 between the leading andtrailing ends of the jacket. In one embodiment, the wall thickness ofthe jacket is gradually increased from a minimum wall thicknessproximate the midpoint between the leading and trailing ends of theprojectile, to a maximum wall thickness proximate the trailing end ofthe jacket. In one embodiment the wall thickness of the jacket proximatethe trailing end of the projectile may be about twice or three times thewall thickness of the jacket at approximately the midpoint between theleading and trailing ends of the jacket.

With reference to FIG. 3, in further embodiment of the presentinvention, the core-bearing jacket is provided with a circumferentialgroove, i.e., a cannelure 36, in the outer surface 30 of the jacket at alocation where it is desired that the disintegration of the projectilealong the length of the jacket diminishes relatively abruptly, even tothe extent that the lower portion 41 of the jacket nearest the trailingend of the projectile is separated unto itself. At this point, the upperportion 43 of the jacket and core nearest the leading end of theprojectile is essentially completely disintegrated. Disintegration ofthe lower portion 41 of the projectile may be halted completely or itmay continue at a lesser intensity and speed of propagation by reason ofthe limiter factor introduced by the presence of the cannelure. Thecontinuation of the disintegration action may serve to effect somedisintegration of the lower portion of the projectile but at the sametime, the intensity and speed of propagation of the disintegration hasreduced to the extent that at least one portion of the jacket proximatethe trailing end of the projectile remains intact and recoverablefollowing impact of the projectile on a target. In the depictedembodiment of FIG. 3, the cannelure defines the limiter factor of thisembodiment of the present invention. it will be recognized that locationof the cannelure along the length of the projectile can be employed toselect the implementation of the limiter factor of the projectile tosuit a given projectile designed for a given application. For example,locating the cannelure nearer or further away from the trailing end ofthe projectile may be employed as a means to produce more or lessdisintegration of that portion of the projectile proximate the trailingend of the projectile when the projectile strikes a target. That is, theproximity of the cannelure limiter factor to the trailing end of theprojectile determines the intensity and rate of progression of thedisintegration front along the length of the projectile in that regionof the projectile between the location of the cannelure and the trailingend of the projectile. for example, the closer the cannelure is to thetrailing end of the projectile, the smaller will be the size of theparticulates of the jacket upon the ultimate completion of thedisintegration action of the projectile. Thus, desirably, the locationof the cannelure along the length of the projectile is proximate themidpoint between the leading and trailing ends of the projectile.

With reference to FIG. 4, in a further embodiment of the presentinvention, there are disposed two cores 18 and 18′ within a singlejacket. In this embodiment, the cores are separated by a disc 44disposed in a plane substantially perpendicular to the longitudinalcenterline 47 of the projectile and between the cores at a locationabout midway between the leading and trailing ends of the jacket. Inthis embodiment, disintegration occurs generally in two phases, thefirst phase involving disintegration of that core 18 nearest the leadingend of the jacket, including dislocation and separation of the disc 44from the projectile. Once the disintegration of the first phase reachesthe disc, the disc no longer has support within the jacket and isimpelled clear of, or generally outside of, the disintegration front andtherefore may remain substantially intact. However, in this embodimentof the present invention, the presence of the disc effectively haltsfurther disintegration of the trailing end of the projectile, so thatthe portion of the core between the location of the disc and thetrailing end of the projectile breaks away as a free intact entity whichmay be recovered for analysis.

Another embodiment of the present invention is depicted in FIG. 5 andincludes a jacket having an internal circumferential ledge 40 defined inthe inner surface of the jacket wall proximate the trailing end of theprojectile. In this embodiment, the ledge defines a limiter factorwhereby disintegration of the projectile progressing from the leadingend of the projectile, is lessened with respect to its rate ofprogression and its intensity of disintegration at the circumferentialledge. Upon the impact of the projectile with a target, this alterationof the disintegration leaves that section 50 of the jacket between thelocation of the ledge 40 and the trailing end of the projectilesufficiently intact as permits identification of the rifling pattern onthe outer surface of this section of the jacket. FIG. 12 schematicallyrepresents a projectile as depicted in FIG. 5, but including a disc 80embedded within the core at the location of the circumferential shoulderinternally of the jacket proximate the midway point between the leadingand trailing ends of the projectile. The disc 80 may be formed from ametallic material, a polymer material or other material suitable fordeveloping a demarcation zone within the core at the location of thedisc. Thus this disc becomes the delimiter factor in this embodiment.

FIG. 6 depicts another embodiment of the present invention which employsmultiple cores 18 and 18′ stacked upon each other within the jacket. Inthis embodiment, that core 18′ adjacent the trailing end 14 of theprojectile is provided with a projection 48 extending away from theleading end of the core 18′. This projection is essentially coincidentwith the longitudinal centerline 47′ of the projectile and is encircledby a soft metal, or like, ring 51 with the outboard end 52 of theprojection being received within a blind bore 54 defined in the trailingend 56 of that core 18 most near the leading end 16 of the projectile.There is no jacket employed in the projectile depicted in FIG. 6.Rather, the projectile is self-supporting.

In this embodiment, the outer diameter of the ring is chosen to beslightly greater than the outer diameter of the projectile so that asthe projectile passes through the rifle barrel, the outercircumferential surface of the ring is imprinted with the riflingmarkings of the barrel.

In the embodiment of FIG. 6, disintegration of the projectile isinitiated at the leading end 16 of the projectile and propagates alongthe length of the projectile. This disintegration is temporarily abateddue to the limiter factor arising at the location of the ring 51 and thejoinder of the stacked cores 18 and 18′. Thereupon the ring, escapes thedisintegration action intact and becomes available for recovery from thetarget for analysis, etc. Following escape of the ring, thedisintegration of the remaining core 18′ of the projectile continues tocompletion.

In FIG. 7 there is depicted a still further embodiment of the presentinvention wherein there are employed multiple self-supporting cores 18and 18′, which are physically coupled to one another by a projection 48extending from the leading end of the core 18′ and received within ablind bore in the trailing end of the core 18. No jacket is employed inthis embodiment.

In this embodiment, that end of the core 18′ adjacent the trailing endof the projectile is provided with a cup-shaped cap 60 of soft metal,tin for example, which overwraps the trailing end of the projectile andextends therefrom up and about the outer surface of a substantialportion of the core 18′. The outer surface 61 of that portion of the capwhich surrounds the core 18′ becomes imprinted with the rifling markingsof the gun barrel from which this projectile is fired.

In this embodiment of the present invention, there are two limiterfactors, the first being the junction 63 of the two cores 18 and 18′ andthe second being the rim 64 of the cap fitted over the trailing end ofthe projectile. When the projectile of this embodiment strikes a targetand disintegrates, the result is a flattening out of the cap, butwithout disruption of the rifling pattern on the outer surface of thecap so that the cap remains intact to the extent needed foridentification of the rifling markings on the cap upon recovery of theintact cap from the target.

The further embodiment of the present invention depicted in FIG. 8, issubstantially identical to the projectile depicted in FIG. 7 with theexception that the cap of FIG. 7 has been eliminated and the outersurface of the projectile has been provided with at least one, andpreferably multiple, elongated metallic flat strip 62 which extendsalong the length of the projectile. As the projectile of this embodimentpasses through a rifled gun barrel, the flat strip takes on the riflingmarkings of the barrel. Upon this projectile striking a target andcommencement of the disintegration of the projectile, the limiter factorprovided by the juncture of the two cores serves to at least dislodgeone or more of the flat strips intact, thereby making these markedstrips available for recovery from the target for analysis. Cocomitally,each of the flat strips provides individual limiter factors which mayabate the rate of progression and/or intensity of disintegration of thepropagating disintegration action of the projectile. Similar to FIG. 7,the projectile of FIG. 8 may be provided with a metal cap fitted overthe trailing end of the projectile, thereby providing a further sourceof intact particulates available for recovery and analysis for riflingmarks thereon.

FIG. 10 schematically depicts a typical intact portion of a projectile,commonly a portion of a jacket, cap, flat strip, ring, or like portion65 of a projectile which has been recovered from a target and showingtypical rifling markings on the portion.

FIG. 9 depicts a round of gun ammunition including a case fitted with aprimer 74 and a projectile disposed in the leading end of the case. Thedepicted projectile of FIG. 9 shows the leading end of the projectileafter closing of such leading end employing an ogive defined on theleading end of the projectile.

FIG. 11 schematically depicts the disintegration of a projectile of thepresent invention upon such projectile being fired into a gel block 70as is well known in the art for observing certain terminal ballistics ofa fired projectile upon it striking a target (the gel block in thisinstance). From FIG. 11 it will be noted that the projectile enters thegel block for a relatively short distance and thereupon commencesdisintegrating into individual particulates. As the elements of theprojectile travel deeper into the gel block, the disintegrationpropagates along the length of the projectile and, in the presentinstance, at least one portion 65, and commonly multiple portions, ofthe projectile remain intact and available for recovery from the targetfor analysis. Whereas herein reference is made to recovery of an intactportion of the projectile from a target, it will be recognized that suchintact portion may “miss” a given target but will be captured in somemedium which is adjacent the actual target. Under these circumstances,the intact portion of the projectile is recoverable from such adjacentmedium and the term “target” is to be deemed to include such adjacentmedium where appropriate.

Whereas the term “gun” has been employed herein for conveniencepurposes, it is to be understood that the projectile of the presentinvention most commonly is of the type which is suitable for being firedfrom a rifle or a pistol having a barrel which includes riflinginteriorly of the barrel.

While the present invention has been illustrated by description ofseveral embodiments and while the illustrative embodiments have beendescribed in considerable detail, it is not the intention of theapplicant to restrict or in any way limit the scope of the invention tosuch detail. Additional advantages and modifications will readily appearto those skilled in the art. The invention in its broader aspects istherefore not limited to the specific details, representative apparatusand methods, and illustrative examples shown and described. Accordingly,departures may be made from such details without departing from thespirit or scope of applicant's general inventive concept. For example,it will be understood by one skilled in the art that the projectile ofFIGS. 6, 7 and 8 which do not include a jacket, as needed or bestsuited, may be individually plated with a non-abrasive coating to avoidabrasion of the rifling of the gun by the projectiles when they arefired from a gun. In one instance, the plating itself may be sufficientthick as to take on the rifling markings of the barrel of the gun fromwhich the projectile was fired and to be recoverable from the target.

1. (canceled)
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 5. An ammunitionprojectile adapted to be fired from a gun having a rifled barrelcomprising: at least one solid core having a leading end and a trailingend and at least one portion of the projectile capable of being markedby the rifling of the barrel of the gun from which the projectile isfired, said core being disintegratable into individual particulates uponthe projectile striking a target, said disintegration commencing at theleading end of the projectile and propagating along the length of theprojectile; at least one limiter factor disposed along the length of theprojectile in the path of the propagating disintegration of theprojectile, said limiter factor at least momentarily abating saidpropagation of said disintegration whereby at least said at least oneportion of the projectile which is capable of being marked by therifling of the barrel of the gun from which the projectile is firedbecoming separated from the projectile intact and recoverable foranalysis, wherein said limiter factor comprises at least one of (a) ajacket having a cannelure defined about the outer circumference of saidjacket at a location between the leading and the trailing ends of thejacket, (b) a jacket having a leading first end and a trailing secondend and an internal circumferential shoulder dividing said first andsaid second ends into first and second portions, said second portionhaving a materially greater wall thickness than the wall thickness ofsaid first portion, (c) first and second cores disposed in stackedrelationship to one another, said first core including a trailing endhaving a blind bore defined therein and said second core including aleading end and a projection projecting from said leading end andadapted to be snugly engaged within said blind bore, (d) first andsecond cores disposed in stacked relationship to one another, and a ringof metallic material interposed between the adjacent ends if stackedcores, a projection extending from one of said adjacent ends in thedirection of the other of said cores, said ring encircling saidprojection, (e) first and second cores disposed in stacked relationshipto one another, said first core including a trailing end having a blindbore defined therein and said second core including a leading end and aprojections projecting from said leading end and adapted to be snuglyengaged within said blind bore, said second core having a trailing endand a cup-shaped cap overlying said trailing end and extending partwayalong the outer surface of said second core in a direction toward saidfirst core, (f) first and second cores disposed in stacked relationshipto one another, said first core including a trailing end having a blindbore defined therein and said second core including a leading end and aprojection projecting from said leading end and adapted to be snuglyengaged within said blind bore, and including at least one elongatedstrip of a metallic material mounted on the outer surface of said coresand extending substantially along the length of said stacked cores and,(g) a jacket having a leading first end and a trailing second end and aninternal circumferential shoulder dividing said first and said secondends into first and second portions, said second portion having amaterially greater wall thickness than the wall thickness of said firstportion and including a substantially rigid disc embedded within thecore at the location of the internal circumferential shoulder.